Portable communication devices, such as cellular telephones, are in common use. Wireless communication devices such as cellular telephones enjoy the convenience of portability. Experience has shown that some users choose to operate a wireless communication device while driving an automobile. Some forms of operation have drawn criticism, citing concerns such as the user using one hand to hold the phone against an ear, thereby making driving an automobile difficult and potentially hazardous, because the hand used for the cellular telephone is not available to operate other controls of the motor vehicle. Dialing a number in a cellular telephone is another commonly expressed concern, in that dialing may be distracting to the driver.
Remote user interface devices have been developed to facilitate a driver's use of a cellular telephone, while still having both hands available to operate the motor vehicle. Such devices may be clipped to the sun visor or other component of the motor vehicle (some may even be “built-in” to the motor vehicle) in a location in which the user may both speak into the device and hear sounds emitted from a speaker therein. The remote user interface device contains a transceiver that wirelessly interfaces with the cellular telephone by a communication protocol, such as, for example, the IEEE standard 802.11 or 802.15.1—2002 (one implementation of which is the Bluetooth® wireless technology developed by Bluetooth SIG, Inc., Bellevue, Wash., U.S.A.). While the cellular telephone is within range, any incoming call utilizes the remote user interface device to communicate with the driver. That is, the audio received by the cellular telephone via the cellular network is fed through a speaker in the remote device for hearing by the driver. When the driver speaks, a microphone in the remote device speaker receives that sound and transmits an audio signal via the wireless link to the cellular telephone for relaying onto the cellular network.